I have not described it in terms of multi tenancy but rather how to run multiple instances of jbpm (-console) on same server if someone would be interested in it. Some could see this as way of supporting multi tenancy but personally I see this is as not the bast way - at least as default one. It depends on your needs and requirements for multi tenancy as this is very broad topic. Do you plan to have multi tenancy as PaaS, or SaaS?
I believe there is nothing out of the box that provides you with complete multi tenancy support but (as already mentioned in the other thread) it is definitely possible. Here you can find some information about a prototype of jbpm-enterprise that provides "infrastructure" for building multi tenant enables applications/systems.
HTH